1. Field of the Invention
The present invention relates generally to the field of personal devices and more particularly to a handheld ubiquitous personal information device.
2. Description of the Prior Art
Several handheld electronic personal devices exist and are commonly used including PDAs and smart cellular telephones. These devices contain computers, browsers, organizers, notepads, telephones, cameras, communications via wireless internet links, Ethernet and telephone as well as other features. Some of these devices contain some means for knowing their location such as GPS. None presently contain altimeters.
In the U.S., new cellular telephones now generally contain GPS receivers for use with the Emergency 911 services as mandated by Congress. Handheld phones in most other countries also contain GPS receivers. Most of these telephones do not perform normal GPS operations and do not continuously keep track of where they are. Rather these telephones usually use schemes such as assisted GPS, triangulation or other methods to help the telephone provider, and hence emergency response personnel, to determine the location of the telephone in the case of an emergency such as a 911 call. Some special services provide continuous GPS location of a handheld unit such as the VIAMOTO system by Motorola Corporation that can be found leased with rental cars. Other types of car navigation systems contain GPS receivers that perform continuous tracking such as those made by Alpine and Garmen.
Altimeters that measure atmospheric pressure to determine elevation have been in use for many years. These pressure devices are very sensitive to changes in atmospheric pressure and must be frequently adjusted to compensate for normal variations in pressure caused by weather phenomena. Without such calibration, such pressure altimeters can be off hundreds of feet vertically. three-satallite (or more) GPS can also report absolute altitude above sea level. However, it is known in the art that a GPS locked on three and even more satellites can be off by more than 50 feet vertically. This has been determined experimentally by comparing raw GPS output altitude readings against geographic benchmarks of known elevation. If less than three satellites are available, GPS cannot normally determine altitude.
Artificial intelligence systems such as expert systems, artificial reasoning, rule-driven systems and inference engines coupled to databases are known in the art to give stored information and expert or reasoned opinions based on stored information. Expert systems that can give detailed data about arbitrary geographic locations or other subjects generally need the support of a large database.
It would be advantageous to have a portable or handheld personal device that contained a cellular telephone or other communications means and could accurately track its position in 3-dimensional space with the help of raw GPS, assisted GPS, or other assisted horizontal techniques, and assisted altimetry that could accurate set the barometric pressure in an internal altimeter for the present horizontal location. This device could then access an internal or external database to provide expert analysis of all information concerning a particular location in 3-dimensional space near the earth (such as the 23rd floor at 1 North LaSalle Street in Chicago, or the 3rd level of the Denver Airport). In particular, this device could answer almost any question about the location and give any advice requested (such as “What are the options for getting to the Airport from where I am in time to catch a 4:00 PM flight. The answer could be: take a taxi or commuter train). Further information could then be given on how or where to do this including step-by-step navigation.